Over the last 40 years, epidemiological studies have shown a disturbing trend of increasing incidence of allergic asthma in children. A wide range of stressors in the womb or during early life can increase the risk of developing allergic childhood asthma. Given the broad spectrum of stressors, it is likely that numerous systems in the body (i.e., the nervous and immune systems) contribute to the observed increase in allergic childhood asthma.

Specialized tissues in the body serve to coordinate immune responses and are required for the development of allergic asthma. These tissues are still developing in the lung during early life and receive signals from various systems that control body functions. We hypothesize that the developing tracheal- and bronchial-associated mediastinal lymph nodes are critical sites where environmental exposures change normal development and set the stage for allergic asthma. The stages of development in humans and other primates is not clear; this study will first examine normal development and the consequences of environmental exposures on immune cells.